South Korea's current account surplus widened in December from the previous month on an increasing exports, with the combined yearly surplus topping the estimate, the Bank of Korea (BOK) said Wednesday.

The current account surplus reached $6.43 billion in December, up from $6.03 billion in November, according to the central bank. The current account is the broadest measure of cross-border trade.

Korea posted a surplus for the 23rd straight month in December, with the combined surplus hitting a record $70.73 billion in 2013, it said.

The BOK's estimate for 2013 was $70 billion in surplus. Its 2014 surplus forecast is $55 billion.

The BOK remained positive about the trend of export growth, saying that the Korean economy is stronger than expected.

The service account, which includes outlays by South Koreans on overseas trips, posted a surplus of $437.6 million last month,compared with a deficit of $697.2 million in November.

The primary income account, which tracks wages of foreign workers and dividend payments overseas, logged a surplus of $419.6million in December, down from a surplus of $588.8 million in November.

The capital and financial account, which covers cross-border investments, posted a net outflow of $6.36 billion in December,compared with a net outflow of $6.33 billion the previous month,the BOK said. (Yonhap)